(Reuters) - U.S. EV battery company Solid Power said on Monday it had partnered with Germany's BMW AG <BMWG.DE> to develop the next-generation solid-state battery technology for use in electric vehicles (EVs).

BMW will assist in advancing Solid Power's technology to achieve performance levels required for high-performance EVs, Louisville, Colorado-based Solid Power said in a statement.

Financial terms of the deal were not disclosed.

All solid-state battery technology is a high-capacity energy storage device that improves on today's lithium-ion batteries, replacing the liquid or gel-form electrolyte with a solid, conductive material. Among other benefits, the new technology offers more capacity and better safety.

Carmakers are trying to lower the cost of electric vehicles by investing in the development of affordable but powerful batteries.

Established in 2012, Solid Power says its solid-state rechargeable batteries could lower costs because of the potential for eliminating many of the costly safety features associated with lithium-ion systems.

Toyota Motor Corp <7203.T>, which has called the technology a "game changer" for EVs, plans to commercialize solid-state batteries and roll out an electric vehicle in the early 2020s powered by them.